tty: serial: mvebu-uart: convert from round_rate() to determine_rate()

The round_rate() clk ops is deprecated, so migrate this driver from
round_rate() to determine_rate() using the Coccinelle semantic patch
appended to the "under-the-cut" portion of the patch.

Signed-off-by: Brian Masney <bmasney@redhat.com>
Link: https://lore.kernel.org/r/20250810-tty-round-rate-v1-1-849009f3bdfd@redhat.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>